Primary amino groups number among the most accessible and ubiquitous of heterocyclic substituents, but they are of little synthetic utility in further synthetic transformations. This research proposal suggest several novel synthetic strategies for effecting (a) the conversion of amino substituents into nitroso groups which, as superb dienophiles, should be versatile intermediates for the elaboration of functionalized alkylamino groups, and for the construction of fused or pendant heterocycles; (b) an in situ procedure for the conversion of amino substituents via intermediate nitroso compounds into nitro groups which can undergo a broad variety of displacement reactions with nucleophiles; and (c) a simple procedure for conversion of substituent amino groups into 1-(4-tosylimidazolyl) groups, which also undergo facile displacement by nucleophiles. With the use of this new chemistry, solutions to a variety of specific synthetic problems are proposed. These new "Umpolung" transformations, designed to allow the conversion of amino groups into a broad variety of other types of substituents under mild conditions, should be of considerable interest and general utility in synthetic heterocyclic chemistry.